Hello, please excuse me, I'm sure this issue has been addresses somewhere. I have built a Whammy amp ~3 years ago with the provided PCB board. I've been using it as a preamp and sounds really amazing. One issue is that if the Whammy is turned off before turning off the main amp, there is a huge popping and puts the amp in protective mode. Is there a way to avoid the "pop" when turning off the Whammy?
This effect is caused by the sudden change of the operating state of the amplifier. As @bigskyaudio said, just follow the queue.
Different opamps will alter this behavior.
This will not work with the stock power supply [1] and heat sinks: has anyone tried bumping bias up to 150-200 milliAmps? Looking at the Id vs Vgs curves in the IRF9610 and IRF610 datasheets hints the MOSFETS could be happier being pushed harder than 60 mA. About 3dB-ish of headroom is lost because Vgs is about 4.5 volts at that drain current, which isn't of much consequence since the headphones are bouncing off my cranium well below clipping. I like the high bias effect but other opinions are always welcome.
[1] I have a bucket load of spare PSU parts so cobbling something up was a doddle.
[1] I have a bucket load of spare PSU parts so cobbling something up was a doddle.
Hello guys. I read in this article about the Whammy needing "output protection" to protect your headphones:
"The power supply is very stable and has negligible noise. I need to point out one thing, there is no output protection. Depending on your opamp and the exact output voltages of the power supply, there will be a thump when powering on, and there is no protection to your precious cans if something goes horribly wrong (DC on output). If you wish to be safe, either a DC blocking capacitor (10kuF/35V) or a speaker protection system can be installed between the amp’s output and the output jack."
https://www.head-fi.org/showcase/diyaudio-whammy.26399/reviews
I have not heard anyone mention this before. Is this really necessary?
"The power supply is very stable and has negligible noise. I need to point out one thing, there is no output protection. Depending on your opamp and the exact output voltages of the power supply, there will be a thump when powering on, and there is no protection to your precious cans if something goes horribly wrong (DC on output). If you wish to be safe, either a DC blocking capacitor (10kuF/35V) or a speaker protection system can be installed between the amp’s output and the output jack."
https://www.head-fi.org/showcase/diyaudio-whammy.26399/reviews
I have not heard anyone mention this before. Is this really necessary?
No it really isn’t. If it does thump just turn it on then plug in the headphones. I can’t tell when it’s on it is so quiet.
This is my review.
Hi Wayne!
I didn't propose the protection as a solution to thump. I meant it as a safety measure for headphones in case of a failure (which is unlikely, but possible). Still didn't come up with a circuit, but I'm thinking about a small add-on board for the output jack. Maybe with a UPC1237 and a SSR.
If you're terrified of amplifier faults applying DC to the headphones (destructively!), you could think about installing a high value capacitor in series between the amplifier and the headphones. Voila, protected against DC faults.
Which is one of my recommendations in the review. Personally, I would rather have a switch (relay or SSR) than a capacitor.
Hi all,
this is my build that I completed a couple weeks ago.
The enclosure is from Aliexpress, really roomy and nice.
regarding the components:
Resistors are Vishay/Dale, Electrolytics mostly Nichicon, film caps are WIMA, pot is Alps blue and connectors Neutrik.
I tried several OPA's (NE5532, OPA2134, LME49720) in different configurations and the winner is...OPA2134 without the 100pf caps (as recommended by Wayne).
Decoupling caps are Nichicon Muse for the moment because I had them in stock, but bipolar UES are already on the list for my next order at Mouser.
I added a EMI filter, it help a lot in my home where my 42HU rack full of IT equipment (3,5kW total) happily pollutes my AC mains...
I followed Nelson's article about grounding basics and kept soignal ground and earth separated by a 35A bridge+cap. It is also the quietest (by far!) when the Whammy is used in more complex setups (e.g. source + DAC + Whammy).
It is an amazing amp (actually, I built 2, one is for my brother). I tried several headphones (AKG k141 monitor, Peerless PMB4, Behringer HPS3000, Sennheiser HD600 and some others). It is just absolutely fantastic, especially with the HD600. Thanks a lot for the design and sharing it, Wayne!
For the moment I run the 10 Ohm resistors for bias (R16/R22/R29/R32), but the amp is running too cool and I like it hot 🙂
I'm thinking of lowering the values to 6,7 or even 4,7 Ohm (I am out of those values - also on the list for the next Mouser order), as some of you guys tried to do so. What are your feedbacks? Is it worth it? Are the Mosfets noticeably happier with more bias?
Cheers,
Denis
this is my build that I completed a couple weeks ago.
The enclosure is from Aliexpress, really roomy and nice.
regarding the components:
Resistors are Vishay/Dale, Electrolytics mostly Nichicon, film caps are WIMA, pot is Alps blue and connectors Neutrik.
I tried several OPA's (NE5532, OPA2134, LME49720) in different configurations and the winner is...OPA2134 without the 100pf caps (as recommended by Wayne).
Decoupling caps are Nichicon Muse for the moment because I had them in stock, but bipolar UES are already on the list for my next order at Mouser.
I added a EMI filter, it help a lot in my home where my 42HU rack full of IT equipment (3,5kW total) happily pollutes my AC mains...
I followed Nelson's article about grounding basics and kept soignal ground and earth separated by a 35A bridge+cap. It is also the quietest (by far!) when the Whammy is used in more complex setups (e.g. source + DAC + Whammy).
It is an amazing amp (actually, I built 2, one is for my brother). I tried several headphones (AKG k141 monitor, Peerless PMB4, Behringer HPS3000, Sennheiser HD600 and some others). It is just absolutely fantastic, especially with the HD600. Thanks a lot for the design and sharing it, Wayne!
For the moment I run the 10 Ohm resistors for bias (R16/R22/R29/R32), but the amp is running too cool and I like it hot 🙂
I'm thinking of lowering the values to 6,7 or even 4,7 Ohm (I am out of those values - also on the list for the next Mouser order), as some of you guys tried to do so. What are your feedbacks? Is it worth it? Are the Mosfets noticeably happier with more bias?
Cheers,
Denis
I'm a genius.
Yesterday evening I placed an order at mouser. As said above, I wanted to try other values for R16/R22/R29/R32. To get free shipping, I added other stuff (not really needed) to my list just to reach the required 50 EUR. Perfect, 50,20 EUR total, I'm so happy I managed to place an order just above the required amount! This morning, I already got shipping confirmation. I'm so happy! But now I am looking at the invoice and guess what I forgot to add to my order? 😡
Sometimes I hate myself.
D.
Yesterday evening I placed an order at mouser. As said above, I wanted to try other values for R16/R22/R29/R32. To get free shipping, I added other stuff (not really needed) to my list just to reach the required 50 EUR. Perfect, 50,20 EUR total, I'm so happy I managed to place an order just above the required amount! This morning, I already got shipping confirmation. I'm so happy! But now I am looking at the invoice and guess what I forgot to add to my order? 😡
Sometimes I hate myself.
D.
I compared various opamps in Whammy, and preferred lme49720 till i tried burson. That is there till now.
...and still we don't learn from it! 🙄
As I am using the standard 2x22V transformer and regulators in the LED topology, how far up can we go from the original 5,1Ohm resistors in he CRCRC filter in order to get a bit more voltage drop to spare the regulators a couple degrees so that I can increase the bias? I have 6,8 Ohm as well as 20 and 22 Ohm 3W ones in stock. Do you see a point of not going that high?
As I am using the standard 2x22V transformer and regulators in the LED topology, how far up can we go from the original 5,1Ohm resistors in he CRCRC filter in order to get a bit more voltage drop to spare the regulators a couple degrees so that I can increase the bias? I have 6,8 Ohm as well as 20 and 22 Ohm 3W ones in stock. Do you see a point of not going that high?
Very interesting. In my case the OPA2134PA was a clear winner over the LME49720 which I usually really like. I guess you like more "analytical" listening or your headphones have a slight roll-off at the hi end of the spectrum?
In my case, a jump from integrated opamps to discretes was massive. I used Muzg Audio opamp and Stacatto Audio ones. First one is super universal, it's a 49720/2134 on steroids. The Stacatto is very tube like since it is a SE design.
Hi everyone - I am new to the forum. Getting all the components together to start building soon.
I can't find a 0.1uF film capacitor for the input protection to ground (as per build guide - they use a red Panasonic cap) at my local electronics store in Perth, Australia. Will a green mylar capacitor of the same capacitance work the same?
I can't find a 0.1uF film capacitor for the input protection to ground (as per build guide - they use a red Panasonic cap) at my local electronics store in Perth, Australia. Will a green mylar capacitor of the same capacitance work the same?